Apple MB417LL User Guide - Page 58

Power specifications:  Voltage: 100 to 240 V AC  Current: 3 A, maximum  Frequency: 50 to 60 Hz Hearing damage Permanent hearing loss may occur if earbuds or headphones are used at high volume. You can adapt over time to a higher volume of sound that may sound normal but can be damaging to your hearing. If you experience ringing in your ears or muffled speech, stop listening and have your hearing checked. The louder the volume, the less time is required before your hearing could be affected. Hearing experts suggest that to protect your hearing:  Limit the amount of time you use earbuds or headphones at high volume.  Avoid turning up the volume to block out noisy surroundings.  Turn the volume down if you can't hear people speaking near you. High-risk activities This computer system is not intended for use in the operation of nuclear facilities, aircraft navigation or communications systems, air traffic control systems, or for any other uses where the failure of the computer system could lead to death, personal injury, or severe environmental damage. 58 Chapter 5 Last, but Not Least